This invention relates to clutch straps for a vehicle clutch assembly, and more specifically, the invention relates to an improved clutch strap design to reduce vibrations when the clutch is disengaged.
Vehicle clutch assemblies are used to break torque between an engine and transmission so that the driver may shift between transmission gears. The clutch assembly includes a clutch cover and pressure plate that moves relative to the clutch cover between engaged and disengaged positions. The engine drivingly rotates the clutch cover and pressure plate together about an axis. The pressure plate is normally in the engaged position in which the engine and transmission are coupled together. When the driver actuates a clutch pedal, the pressure plate is moved to the disengaged position. Resilient clutch straps secure the pressure plate to the clutch cover to transmit torque from the clutch cover to the pressure plate and allow axial movement between them. Typically, the clutch straps are spaced from and transverse to the axis near an outer perimeter of the pressure plate. The clutch straps flex as the pressure plate moves between the engaged and disengaged positions.
The clutch straps have opposing ends that are connected to the clutch cover and pressure plate. In the prior art, the clutch straps are straight in a free state and are bent in the disengaged and engaged positions so that the clutch straps ends are spaced from one another. Said another way, the ends are in planes perpendicular to the axis, which are offset from one another. Because of the rotation of the clutch cover and the pressure plate, moments are generated at the ends, which in the presence of torsional vibrations cause axial vibrations. These vibrations may cause misadjustments in self-adjusting clutches that may compromise the operation of the clutch. Therefore, what is needed is an improved clutch strap design that minimizes axial vibrations and misadjustments caused by the rotation of the clutch cover and pressure plate.
The present invention provides a clutch assembly for a vehicle including a clutch cover rotatable about an axis. A pressure plate is also rotatable about the axis and is movable along the axis relative to the clutch cover between engaged and disengaged positions. A resilient clutch strap secures the clutch cover and pressure plate together so that they rotate together about the axis. The strap transmits torque from the clutch cover to the pressure plate and allows axial movement between them. The strap is spaced apart from and transverse to the axis. As the pressure plate moves between engaged and disengaged positions, the resilient clutch strap flexes. The resilient clutch strap has first and second opposing ends secured to the clutch cover and pressure plate, respectively, at first and second connections, respectively. The first connection defines a first plane perpendicular to the axis, and the second connection defines a second plane perpendicular to the axis. The resilient clutch strap includes a disengaged state in which the first and second planes are generally coplanar in the disengaged position.
Accordingly, the above invention provides an improved clutch strap design that minimizes axial vibrations and misadjustments caused by the torsional vibrations from rotation of the clutch cover and pressure plate.